Family members identified the toddler shot and killed in Lancaster as 2-year-old Jacarion Gladden.

Police arrested Toni Gladden and her boyfriend Shazeem Hayes in connection with the shooting incident.

"Last night was probably the darkest night in the history of the Lancaster police department at least in the 20 something years I've been here," said Grant.

Police said so far in the investigation that there is "nothing that suggests that the death of Jacarion Gladden was an intentional act." However, investigators suggest that extreme criminal negligence was a major factor in the 2-year-old's death, police said in the press release.

Toni Gladden and Hayes were each charged with unlawful conduct toward a child. According to public records, Gladden has had an aggravated assault charge against her in 2006 and Hayes pled guilty to burglary and unlawful carry of weapons charges in 2016.